1. Field of the Invention(s)
The invention(s) relates to fire resistant materials and formulations thereof, and in particular to organic/inorganic composites suitable for use as fire resistant materials.
2. Description of the Related Art
Plastic and its composites are widely used in various fields such as sports equipment, indoor decoration materials, building materials, industrial and civil engineering projects, electronic products, automobiles, and so on. However, because plastics are flammable material, fire caused by plastic materials result in enormous personnel casualty and financial losses every year. It is therefore an important research topic to develop an environmentally-friendly fire resistant polymer material or composite that effectively reduces personnel casualty and financial loses due to plastic material fires, while also not causing pollution to the ecology.
Due to growing environmental concerns, there is a clear trend and need to develop halogen-free flame retardant systems. Examples of halogen-free flame retardants include magnesium hydroxide, and aluminum hydroxide. The flame retardant effects of aluminum hydroxide and magnesium hydroxide are based on endothermic decomposition into metal oxide and water, respectively. The plastic is protected from rapid thermal decomposition and the formation of flammable and combustible breakdown products are inhibited. The water vapor that is formed displaces oxygen and functions as protective gas. A heat resistant covering layer including carbonized products and metal oxide is formed on the surface of the plastic, thereof inhibiting combustion, which also reduces smoke density. Metal hydroxide is the most popular halogen-free flame retardant and can be used independently or in combination with other flame retardants to provide fire resistant thermosetting or thermoplastic composites.
Metal hydroxide, for example, aluminum trihydroxide (ATH), includes many —OH groups and usually has moisture adhered to its surface, and therefore has a very high polarity. Therefore, when metal hydroxide is blended with polymer resin, which generally has a low polarity, agglomeration occurs due to poor interfacial compatibility. In addition, because the polymer does not react with metal hydroxide to form a well-structured composite by the formation of chemical bonds, the resulting product easily melts, ignites, or produces flame drippings under exposure to flames. Moreover, the incorporation of metal hydroxide greatly increases the brittleness of the material, thus limiting application fields.
Accordingly, there exists a need for an organic/inorganic composite wherein the inorganic particle has improved polymer compatibilities to provide better flame retardancy and reduced brittleness.